This application claims the benefit of Korean Patent Application No. 10-2011-0034523 filed on Apr. 14, 2011. All of the contents disclosed in the description and drawings of this application are incorporated herein by reference.
Cone-shaped crushers are very important crushers in aggregate and mineral processing industries. Various structures and types have been developed for a variety of uses.
Korean Patent Registration No. 10-0809900 discloses a cone-shaped crusher including an eccentric drive that makes the main shaft undergo a gyratory movement. The cone-shaped crusher includes a frame with a cavity, a main shaft disposed in the frame, and an eccentric driving means connected to a lower end portion of the main shaft. The lower end portion of the main shaft is inserted into an opening formed in an upper portion of the eccentric driving means. Three bearings including an upper bearing, a central bearing, and a lower bearing are provided in the vicinity of the lower end portion of the main shaft, and the main shaft is fitted into the central bearing among the bearings. On the upper portion of the eccentric drive is formed an opening and the diameter of it is larger than that of the outer diameter of the central bearing in order to put the central bearing into the eccentric drive. The upper bearing is fitted on the upper end of the eccentric drive after forming a separate mount so as to be eccentric from the opening. Therefore, the internal diameter of the upper bearing is larger than the outer diameter of the central bearing, and the size of the upper bearing becomes inevitably very large.
Generally, the cone-shaped crusher is a large-size machine, and a bearing to be used as the upper bearing should be much larger than the size of a widely used standard bearing and is not readily available in the market. Therefore, the bearing should be made to order. However, as the size of the bearing gets larger, there is a problem in that the costs increase rapidly, therefore, the costs for replacing the upper bearing are huge. In addition to such high cost, with the bearing size increasing, rated rotating velocity is gradually slowed which limits the operation velocity of the cone-shaped crusher. This means that the capacity of the crusher is limited and low efficiency crushers are obliged to be made due to big upper bearings